1. Field of the Invention
The present invention relates to a cleavage apparatus used for liberating a peptide assembled on a solid support by a solid-phase peptide synthesis.
2. Discussion of the Related Art
Generally, synthesis of DNA, RNA and peptides (hereinafter simply referred to as peptide synthesis) has been achieved by repeating a series of treatments of washing, coupling, washing and deprotection on a solid-support of glass beads or resin powder in a filter-attached reaction vessel. Also, in order to obtain a free peptide, a cleavage procedure is necessary after the above-mentioned treatments.
The chemical synthesis of a peptide requires extensive knowledge and sophisticated techniques, and amino acid derivatives for peptide synthesis are expensive. Therefore, the resulting peptide is referred to as a highly value-added substance. Reagents and therapeutics or diagnostic agents containing chemically synthesized peptides have sometimes brought a vast amount of profit. When such synthesized peptide is used for practical purposes, a relatively large amount is needed, i.e., at least 10 to 20 mg is necessary for use in research and more than 100 g for commercial use, pre-clinical tests or clinical use. A large scale or at least semi-large scale synthesis is thus indispensable for practical purposes.
However, in such a larger scale peptide synthesis using a conventional method (Boc-chemistry), a special reactor or cautious operation is needed because extremely dangerous reagents such as hydrogen fluoride or trifluoromethanesulfonic acid (TFMSA) are used in large quantities at the final step of the cleavage procedure. In recent years, Fmoc-chemistry of solid-phase peptide synthesis has widely been used in the field of peptide chemistry, which permits cleavage treatment under less dangerous conditions. In the Fmoc-polyamide method, cleavage is done using TFA (trifluoroacetic acid). TFA is not a totally safe reagent and necessitates careful handling. The danger of TFA used in large quantities is still an actual concern in the field of art. Therefore, the development of a cleavage apparatus which permits easy, safe, rapid and reliable cleavage in a large scale peptide synthesis has long been sought.